In order for one to compete in all bowling meets, it is necessary to use a solid bowling ball fabricated from non-metallic material. The ball must be 27 inches in circumference and must be machined into a preferably spherical geometrical configuration. A top weight must be located in proximity of the finger holes so that the loss in weight from the drilling of the finger holes results in a ball having equal weight distribution within the limits specified by the ABC Rules. The weight of the ball must be between 10-16 pounds. When the ball is weighed with the finger holes "looking-up" and the thumb hole is positioned adjacent to the weigher, the imbalance to the left and right and fore and aft must be no more than 1 ounce and the imbalance between the top and bottom must be no more than 3 ounces. Accordingly, there are very few expedients which can be employed in order to enhance the gyroscopic effect produced by the ball as it rolls down the bowling lane towards the bowling pins.
Others have attempted to provide a gyroscopically stabilized bowling ball, as for example, Randolph U.S. Pat. No. 3,865,369 provides a weighted insert located near the top side of the mid-plane of the ball which provides a dual function of a top weight and a means by which the ball is gyrostabilized. Luth, U.S. Pat. No. 2,291,738 provides a bowling ball having an inner core arranged to maintain the ball in correct balance by the provision of an annular or toroidal centrally located member of heavier material.
Bowling balls must be made in various different weights according to the purchasers' demand. At the same time, the top weight must be varied in order that different size finger holes may be formed within the ball while at the same time the ABC Rules are satisfied. There can be no discernible metal in the bowling ball and the ball must be of solid construction. Therefore, in order to maintain a constant diameter, provide a top weight, and at the same time provide balls which vary in weight from 10-16 pounds, the selection of the materials of construction must be relied upon in order to obtain a specific gross weight. This can be achieved by surrounding a relatively light weight core with a heavier main body, and additionally providing a still more dense top weight which is calculated to offset the loss in weight resulting from the drilling of the finger holes.
In my previous U.S. Pat. No. 4,121,828, there is taught a bowling ball having a top weight arranged in a configuration which effects a gyroscopic action when the ball is rolled. The present invention provides a ball having a light weight core arranged in such a manner that the resultant main body is of a geometrical configuration which effects a gyroscopic action when the ball is rolled.